<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>开发阶段</title>
</head>
<body>
  <div id="app"></div>
  <script src="https://cdn.staticfile.org/react/17.0.1/umd/react.development.min.js"></script>
  <script src="https://cdn.staticfile.org/react-dom/16.8.0/umd/react-dom.development.js"></script>
  <script src="https://cdn.staticfile.org/react-router-dom/5.2.0/react-router-dom.min.js"></script>
</body>
</html>